Selected case studies
Seasonal changes in wolf-caribou overlap
- Seasonal changes in resource selection and prey use by wolves resulted in changes in spatial overlap between wolves and threatened woodland caribou and in the number of caribou killed by wolves.
In winter, the probability of wolfves using upland forests, where white-tailed deer were most abundant, was highest; this resulted in little spatial overlap with caribou and in low caribou mortality by wolves.
In summer, wolves switched to hunting primarily beaver which are common in caribou range. This seasonal prey switching resulted in an increased probability of wolfes using habitats preferred by caribou and in an increased number of caribou killed by wolves at this time of year.
Full details: Latham ADM, Latham MC, Knopff KH, Hebblewhite M, Boutin S. 2013. Wolves, white-tailed deer, and beaver: implications of seasonal prey switching for woodland caribou declines. Ecography. doi: 10.1111/j.1600-0587.2013.00035.x.
Wolf movements in modified landscapes
- Extensive networks of industrial linear features (e.g. pipelines, roads, seismic lines (linear clearings used to identify oil, gas and mineral deposits)) criss-cross large sections of the Boreal forest of Alberta, Canada. These features are believed to affect predator-prey dynamics by increasing wolf hunting efficiency within endangered woodland caribou range.
Wolves showed strong selection for seismic lines as movement corridors, particularly during summer when most caribou mortalities occur.
Wolf use of seismic lines increases risk of predation for caribou close to these features, resulting in caribou avoidance of linear developments and thus functional loss of otherwise suitable habitat.